Groundfish Assessment Program Bottom Trawl Surveys

Duane Stevenson (duane.stevenson@noaa.gov): Eastern Bering Sea and Northern Bering Sea Survey Team Lead

Ned Laman (ned.laman@noaa.gov): Aleutian Islands and Gulf of Alaska Survey Team Lead

Susanne McDermott (susanne.mcdermott@noaa.gov): Aleutian Islands Survey Team Lead

What we do

Who is conducting the research?

Scientists from the Alaska Fisheries Science Center’s Groundfish Assessment Program (GAP) conduct these bottom trawl surveys with participation from the Alaska Department of Fish & Game (ADF&G), the International Pacific Halibut Commission (IPHC), universities, and other organizations. This research is conducted primarily on chartered fishing vessels.

What is the research objective?

The objectives of these surveys are to: 

• monitor the population and environmental trends in the marine ecosystem of the Bering Sea, Aleutian Islands, and Gulf of Alaska, 
• produce fishery-independent biomass (weight) and abundance (number) estimates for commercially important fish and crab species, and 
• collect other biological and environmental data for use in ecosystem-based fishery management.

Communications

Publications

Publications by the GAP team and collaborators are available online through the NOAA Institutional Repository. 

Annual Data Report Tech Memos

The Alaska Fisheries Science Center uses the NOAA Technical Memorandum series to issue technical publications that reflect sound professional work and may be referenced in the formal scientific and technical literature. These are available online through the NOAA Institutional Repository.

Latest Annual Data Reports:

• (2024) Results of the 2023 eastern and northern Bering Sea continental shelf bottom trawl survey of groundfish and invertebrate fauna 
• (2023) Data Report: 2022 Aleutian Islands bottom trawl survey
• (2024) Data report: 2023 Gulf of Alaska bottom trawl survey 
• (2016) Results of the 2016 eastern Bering Sea upper continental slope survey of groundfishes and invertebrate resources 

Northern Bering Sea Groundfish and Crab Trawl Survey Community Highlights

GAP compiles survey findings for communities in Alaska’s northern Bering Sea region. Please note: These documents are for informational purposes only and do not necessarily represent the views or official position of the Department of Commerce, the National Oceanic and Atmospheric Administration, or the National Marine Fisheries Service. Not to be cited without permission from the authors.

• 2023 and Strait Science seminar series recording
• 2022 and Strait Science seminar series recording
• 2021 and Strait Science seminar series recording
• 2019 and Strait Science seminar series recording
• 2018
• 2017
• 2010

North Pacific Groundfish Plan Team

Each year, the GAP survey teams present their findings to the North Pacific Groundfish Plan Team. Recordings of these presentations with relevant attachments are available on the North Pacific Fishery Management Council website. 

Research Briefs

Each year, the GAP produces research briefs, or research plans, of their upcoming surveys and research. 

Maps of Temperature and Survey Progress

Maps of near real-time temperatures from each of the GAP’s bottom trawl surveys are posted each business day of the survey. Water temperature affects many species' spawning times, access to food, growth rates, and overall distribution. Collecting temperature data helps better understand species’ habitats and the larger ecosystem.

Bottom Trawl Survey Photo Gallery

Explore our photo gallery to see this current survey’s photos from scientists in the field. These photos show incredible places that NOAA scientists go and showcase our mission in ways that words cannot.

Open Data and Tools

Open Data Science Tools

Please visit GAP’s GitHub organization for the latest tools, analyses, and data products developed by GAP scientists and collaborators. 

Publicly Accessible Survey Data: Fisheries One Stop Shop

The final, validated survey data are publicly accessible soon after surveys are completed on the Fisheries One Stop Shop (FOSS) platform. This data set includes catch, haul, and environmental information collected at each station. On the FOSS data platform, users can interactively select, view, and download data. Descriptive documentation and user-examples are available on the metadata page.

Stock Assessment Survey Data: Alaska Fisheries Information Network (AKFIN)

The final, validated survey data and standard data products are accessible soon after surveys are completed on the Alaska Fisheries Information Network (AKFIN). This series of data tables includes catch-per-unit-effort, biomass, abundance, size composition, and age composition data. Descriptive documentation and user-examples are available on the metadata page.

NOAA Fisheries Distribution Mapping and Analysis Portal (DisMAP)

Data provided by the FOSS platform are used in the NOAA Fisheries Distribution Mapping and Analysis Portal (DisMAP) to map fishery-independent survey results and to provide easy access to information that helps track and understand distributions of marine species in U.S. Marine Ecosystems.

Requests

Data Requests

Data that are not available as standard data products on these platforms can be requested by submitting an issue to us on our GitHub repository or by emailing our team at nmfs.afsc.gap.metadata@noaa.gov. We also accept suggestions for changes to our standard data products and will respond to your request as soon as possible.

Special Projects Requests

There are opportunities to conduct scientific projects in addition to our typical stock assessment collections. Interested parties are instructed to fill out a Collection Request Form. Completed request forms received by the submission deadline are required for the consideration of all projects and collections. The special projects conducted on the surveys are summarized in our annual data report tech memos.

Resources

Code Books

The Species and Gear Code book is a listing of codes used in RACE Division surveys. 

Survey Protocols

Groundfish bottom trawl survey protocols are documented in NOAA protocols for groundfish bottom trawl surveys of the nation’s fishery resources. 

Volunteer with us!

Are you interested in joining us on one of our surveys? GAP regularly takes students and volunteers at all levels aboard with them.  Our surveys are a great hands-on learning opportunity for students and scientists, alike. Please be aware that we work twelve-hour day shifts in all kinds of weather and sea conditions. During surveys, the work includes identifying and sexing fish, lifting rocks and heavy baskets, and taking biological samples. Volunteers will need to meet required medical, training, and security clearances. We welcome your participation! We appreciate your serious commitment and contributions to these high-quality datasets. Please submit inquiries to nmfs.afsc.gap.metadata@noaa.gov.

Collaborators

Our data are used in many annual publications including, but not limited to, the list below: 

• Alaska Stock Assessments
• North Pacific Groundfish Stock Assessment and Fishery Evaluation Reports
• Groundfish Economic Status Reports for the Gulf of Alaska and Bering Sea and Aleutian Islands
• Alaska Marine Ecosystem Status Report Database
• Southeast Alaska Coastal Monitoring Survey Reports
• Alaska Fisheries Life History Database
• Essential Fish Habitat Research Plan in Alaska

Acknowledgments

We thank the many communities of Alaska and their members who have helped contribute to this body of work. The knowledge, experiences, and insights have been instrumental in expanding the scope of our science and knowledge to encompass the many issues that face this important ecosystem. We appreciate feedback from those residing in the region who are willing to share their insights and to participate in an open dialog about how we can improve our collective knowledge of the ecosystem and the region.